OncoLink eNews: On the Forefront of Colorectal Cancer, Fall 2002

Ultima Vez Modificado: 22 de septiembre del 2002

Volume 2, Issue 4

OncoLink would like to recognize the contribution of the National Colorectal Cancer Research Alliance (NCCRA) whose initiative with Pharmacia Oncology and Pfizer has made this publication possible.

Study Finds Katie Couric's Effort Prompted Many Colonoscopies

In March of 2000, Katie Couric, NBC Today Show co-anchor and co-founder of the National Colorectal Cancer Research Alliance, underwent her first colonoscopy. Ms. Couric's colonoscopy was unusual in that it was televised on the Today Show, for millions of viewers to watch. Katie, whose husband, Jay Monahan, died of the disease at age 42, hoped to show viewers that the test was not a big deal and that it had the ability to save many lives through early detection.

A study conducted by the University of Michigan found that Katie had succeeded. The study included colonoscopies performed by 400 gastroenterologists nationwide from July 1998 (89 weeks before Ms. Couric's test) to December 2000 (40 weeks after her test). The researchers saw an increase of 19% in the number of screening tests performed during that period.

Katie says she's "thrilled people paid attention and took action." Her challenge is to keep the positive effects going. This past March Ms. Couric underwent a "virtual colonoscopy" on the air, a procedure that is still considered experimental. Once again, her efforts have prompted people to discuss this "unspeakable" disease with family, friends, and healthcare providers, and become more aware of the disease and the available screening tests.

Some helpful prevention and risk evaluation tips:

Prevention Tips: There are simple steps anyone can take to greatly reduce their risk of this preventable, yet deadly, cancer.

• Know your family. If an immediate family member has had colon, rectal, breast, prostate, testicular, or another glandular cancer, you should be tested when you are 10 years younger than they were when diagnosed.
• Exercise. Even a small amount each day can work towards reducing colon polyp growth.
• Hormone Replacement Therapy. If you are a woman, and are past the age of menopause, studies have shown a promising link between hormone replacement therapy and reduced colorectal polyp growth. You should discuss your particular case with your doctor.
• Calcium & Folic Acid. Recent research has found that daily calcium and folic acid supplements, taken over a long period of time, may reduce your chances of developing colorectal cancer.
• Aspirin or Cox-2 pain relievers. Taking an aspirin a day also has been proven to reduce pre-cancerous colon polyp growth. Preliminary studies have shown reductions for newer, similar prescription pain medications.

Risk Factors: Both men and women are at equal risk for colorectal cancer. The older you are, the higher your risk; nevertheless, 13,000 cases per year will still be diagnosed in people under 50.

African Americans have higher colorectal cancer rates than men and women of other racial and ethnic groups.

Unhealthy habits like smoking or being overweight increase your risk for colorectal cancer. An important risk factor is having a family history or personal history of the following:

• Colorectal Cancer
• Inflammatory Bowel Disease
• Colon Polyps
• Cancer of the Breast or any Gland

Colorectal Cancer Screening

By: James Metz, MD

It is estimated that more than 131,000 Americans will develop colon or rectal cancer in 1998. It is the second most common cause of death from cancer in the United States. Colorectal cancer can be treated effectively when it is discovered at an early stage of disease.

There are a number of risk factors associated with the development of colorectal cancer. Hereditary colon polyps, cancer family syndromes, and a history of colorectal cancer in a first-degree relative all place the individual at a higher risk. A personal history of adenomas and colon polyps, previous colorectal cancer, or inflammatory bowel disease also puts the individual at higher risk. However, less than 1/3 of patients diagnosed with colorectal cancer have high-risk features. There is an increased risk of developing colorectal cancer with increasing age. For this reason, it is recommended all individuals over the age of 50 participate in colorectal cancer screening.

There are a number of screening tests utilized for colorectal cancer:

Digital Rectal Examination: The physician inserts a gloved finger into the rectum and feels for any abnormalities. If no blood is visible on the gloved finger, fecal occult blood testing is performed (see below). To date, there has not been significant evidence that the rectal examination has had any effect on mortality when used alone as a screening test.

Fecal Occult Blood Testing: Special cards are utilized to test for occult blood (blood not seen by the naked eye). Patients can place a small sample of feces on the card at home or the physician can place a sample on the card after a digital rectal examination. A special chemical is used by the lab to determine if blood is present. It should be noted many things could cause a positive occult blood test. If you have a positive test, further studies are warranted. Fecal occult blood testing on an annual or biannual basis for individual 45-80 years of age has been shown to decrease mortality from colorectal cancer.

Sigmoidoscopy: A sigmoidoscope is a thin tube with a light at the end, which is placed into the rectum. It can evaluate the distal colon and the rectum (about 1/3 of the colon) for polyps, tumors, and other abnormalities. Regular screening in individuals over 50 years of age may decrease mortality from colorectal cancer. There has been significant controversy over the optimal screening interval.

Colonoscopy: The colonoscope is much longer than a sigmoidoscope so that the entire colon can be evaluated. Patients are usually sedated for a colonoscopy procedure. A colonoscopy may be recommended for patients who are at high risk for colorectal cancer, have abnormalities on a sigmoidoscopy, or have unexplained fecal occult blood.

Barium Enema: A barium enema is a radiologic study of the colon and rectum. Barium is contrast material that is given by enema prior to taking X-rays. This allows the colon and rectum to be visualized and abnormalities can be evaluated. The patient is placed on a table that moves so the contrast can be followed through the bowel.

The American Cancer Society recommends three courses of action beginning at the age of 50, from which the patient and physician can choose for screening. These include:

• Annual fecal occult blood tests, together with a flexible sigmoidoscopy and digital rectal examination every 5 years.
OR
• Colonoscopy with digital rectal examination every 10 years
OR
• Double contrast barium enema with digital rectal examination every 5-10 years

Ask the Experts

Dear OncoLink "Ask The Experts,"
What role does diet play in the prevention of colon cancer?
Thanks.

Katrina Claghorn, MS, RD, Registered Dietitian at the University of Pennsylvania Cancer Center, responds:

There has been a great deal of research on the impact of nutrition on colon cancer. Despite all the studies there is still no definitive anti-colon cancer diet. Below is a list of nutritional factors that have been found to have the greatest potential for reducing colon cancer risk.

• A high intake of dietary fat, especially saturated fats mostly found in animal sources, has been shown to increase the incidence of colon cancer. Red meat in particular has been associated with increasing risk. Include more fish, poultry and low fat dairy products in your diet.
• Fiber was long considered an important preventive factor, however recent research has been conflicting. It is still wise to strive for at least 25 grams of fiber a day for general good health.
• High levels of calcium have been associated with decreased polyp formation. While dietary sources of calcium are encouraged, calcium supplements were also found to be beneficial.
• Folic acid acts to prevent damage to DNA, which can trigger the cancer process. While folic acid is found in dark green vegetables and dried beans and legumes, it is now added to enriched breads and cereals.
• Some studies indicate that the antioxidant vitamins A, C and E, as well as the mineral selenium may reduce the incidence of colon cancer. While the benefits of taking supplements of these nutrients are still being debated, adding more fruits and vegetables to your diet is advised.
• Obesity is associated with increased risk of developing colon cancer. Try to maintain a healthy weight.
• Regular exercise has also been found to be protective.

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